<!DOCTYPE html>
<html>
    <head>
        <style type="text/css"> 
            #div1{
                width:100px;
                height:100px;
                padding:50px;
                color:white;
                background-color:red;
                }
            #div2{
                width:100px;
                height:100px;
                color:white;
                background-color:blue;
            }
        </style>
    </head>
    <body>
        <div id="div1">设置padding</div>
        <div id="div2">未设置padding</div> 
    </body>
</html>